KR100306483B1 - ATM Cell Mulitplexing System - Google Patents

Abstract

The ATM cell multiplexing device relates to an ATM cell multiplexing device which assigns a priority to each board in which a transferable cell exists so that the multiplexing is performed according to the priority.

The present invention includes a plurality of subscriber boards for storing ATM subscriber cells received from each link in a FIFO, and a multiplexing board for reading and multiplexing cell information stored in the FIFO of the subscriber board according to an assigned priority. ATM cell processing that collects the information of the board and gives the priority to each subscriber board, and then checks the information of the subscriber board again to determine the corresponding slot number, and then activates the reading of cell information of the corresponding slot. It further comprises a means.

Therefore, the reliability of the operation of the ATM switching system can be provided by accommodating a larger number of subscriber boards to perform the multiplexing process.

Description

ATM Cell Mulitplexing System

The present invention relates to an Asynchronous Transfer Mode (ATM) cell multiplexing device. More particularly, when accommodating a plurality of subscribers, multiplexing is performed according to priority by giving priority to each board in which a transferable cell exists. The present invention relates to an ATM cell multiplexing device.

In general, an ATM user network interface is an interface between a subscriber network including a user terminal and a communication network provider, and provides a DS3 (Digital Signal Level 3) interface having a transmission rate of 45 Mbps with each link on the subscriber network side. It provides STM-1 (Synchronous Transport Module Level 1) interface with transmission line and transmission rate of 155.52Mbps.

As shown in FIG. 1, the configuration of a cell multiplexing device in an ATM user network interface includes a plurality of DS3 processing units 11-13 and a single STM-1 processing unit 14, each DS3 processing unit 11-13. ) Stores the subscriber cell in FIFO (First In First Out) when the DS3-class subscriber cell, the 53-byte ATM cell, arrives from the corresponding link and transmits the cell input to the STM-1 processor 14 to the subscriber cell. Report the arrival of.

The STM-1 processing unit 14 sequentially reads the DS3 processing units 11-13 according to the set priority, and then selects a cell selection signal to the FIFO of the DS3 processing unit 11-13 that has received the fact that the subscriber cell has been input. Reads the subscriber cell stored in the FIFO, multiplexes it into STM-1 class transmission frame, and transmits it to the network operator.

An operation of multiplexing a subscriber cell in an ATM cell multiplexer having the above function will be described with reference to FIG. 2.

When the subscriber cell is input to the corresponding DS3 processor 11-13 in the cell input period from the subscriber link, the corresponding DS3 processor 11-13 that has received the subscriber cell information is activated with the cell status information. B and C) are stored in the FIFO, and the cell input is reported to the STM-1 processor 14 side.

At this time, the STM-1 processor 14 sequentially activates logic for selecting the DS3 processor 11-13 and sequentially reads the DS3 processor 11-13 according to the set priority. When the first link to the second link to the third link is set, the STM-1 processing unit 14 outputs a cell selection signal at the set priority and thus, the subscriber cell stored in the FIFO of each DS3 processing unit 11-13, that is, the first link. 'A' from the link, 'B' from the second link, and 'C' from the third link are read in sequence and then multiplexed into STM-1 class frames with a transmission rate of 155.52 Mbps to the network operator. .

As described above, when the transmission process after the multiplexing with respect to the subscriber cell of the first priority is completed, the STM-1 processor 14 activates logic for selecting the DS3 processor 11-13 to multiplex the next subscriber cell. For example, if a subscriber cell arrives at the first DS3 processing unit 11 and the third DS3 processing unit 13 through the first link and the third link and is stored in the FIFO, the first and third DS3 processing units ( 11) 13 notifies the STM-1 processor 14 of the arrival of the subscriber cell.

At this time, the STM-1 processor 14 transmits a cell selection signal to the first link and the third link according to the set priority and is stored in the FIFOs of the first DS3 processor 11 and the third DS3 processor 13. The subscriber cells 'D' and 'E' are sequentially read and then multiplexed into STM-1 class frames with a transmission rate of 155.52 Mbps and transmitted to the network operator.

Since the above operation is repeatedly performed, the subscriber cell multiplexed by the STM-1 processor 14 is performed in the order of 'A → B → C → D → E → F → G → H → I → J'.

In case of multiplexing subscriber cells in the conventional ATM cell multiplexer as described above, the collection of subscriber link information is additionally performed when the number of subscriber links is increased because the collection of subscriber link status information and cell processing are sequentially performed according to the set priority. There is a problem that the time required to actually process the ATM cell is relatively reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described general problems, and an object thereof is to detect whether a deliverable cell exists from the state information of a subscriber board to be collected, and then assign a priority to each board in which the deliverable cell exists, thereby providing a plurality of subscribers. In this case, it provides speed for the ATM multiplexing process and accommodates more subscriber boards to increase the cell multiplexing processing capacity.

1 is a block diagram of a cell multiplexing device in a typical ATM user network interface.

2 is a diagram illustrating cell multiplexing in a cell multiplexing apparatus of a conventional ATM user network interface;

3 is a block diagram of an ATM cell multiplexing device in an ATM user network interface according to the present invention;

4 is a detailed configuration diagram of an ATM cell processing unit in FIG. 3.

<Explanation of symbols for main parts of the drawings>

310: subscriber information collection unit 320: connection control unit

330: cell processing unit

The present invention for achieving the object as described above, in the ATM switching system, a plurality of subscriber boards for storing ATM subscriber cells received from each link in the FIFO, and stored in the FIFO of the subscriber board in accordance with the assigned priority And a multiplexing board that reads and multiplexes cell information, and if there is a cell that can collect and transfer information of the plurality of subscriber boards, gives priority to each subscriber board, and then checks the information of the corresponding subscriber board once again and checks the corresponding slot number. After confirming, further comprising ATM cell processing means for activating the reading of the cell information of the slot.

The ATM cell processing unit collects the information of each subscriber board connected to the subscriber link and then assigns a priority for each subscriber board in which a transmittable cell exists, and the state information of the board selected by the subscriber information collector. Checks once more to determine whether the selection of the board is successful, and reads the cell of the corresponding time slot from the subscriber board according to the information of the connection control unit, and transmits the cell to the multiplexing board. Completion of the information is sent to the subscriber information collecting unit side characterized in that the cell processing unit for controlling the multiplexing of the next cell.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As can be seen in Figure 3, another ATM cell multiplexing apparatus according to the present invention includes a plurality of subscriber boards (100A-100N) having a DS3 processing unit and a multiplexing board (200) and an ATM cell processing unit provided with an STM-1 processing unit ( 300. When the 53-byte ATM cell arrives from the corresponding subscriber link, the subscriber board 100A-100N stores the subscriber cell in the FIFO and informs the ATM cell processor 300 of the arrival of the cell. The subscriber station transmits the corresponding subscriber cell stored in the FIFO to the multiplexing board 200 according to the cell selection signal applied from the ATM cell processing unit 300.

The multiplexing board 200 reads subscriber cells sequentially applied from the FIFOs of the subscriber boards 100A-100N and multiplexes them into STM-1 class frames having a transmission rate of 155.52 Mbps and transmits them to the network operator.

The ATM cell processing unit 300 collects the FIFO information of each subscriber board 100A-100N connected to the subscriber link, determines whether there is a transferable cell, and then assigns priority to each subscriber board 100A-100N. Check the cell information stored in the FIFO of the selected subscriber board (100A-100N) once again to determine the corresponding slot number, and activates the reading of the cell information of the determined corresponding slot to transmit to the multiplexing board 200 side. .

As shown in FIG. 4, the ATM cell processing unit 300 includes a subscriber information collection unit 310, a connection control unit 320, and a cell processing unit 330.

The subscriber information collecting unit 310 collects the information of the corresponding FIFO of the subscriber board 100A-100N connected to each of the plurality of subscriber links, and then scans the whole while increasing the slot number by one by one the ATM cell information stored in each FIFO. After assigning priority to each subscriber board, the information on the selected subscriber board is applied to the connection control unit 320.

In this case, the priority of each subscriber board is given the lowest priority of the board currently being processed by the ATM cell, and the highest priority is given to the subscriber board of the slot for the next processing. To be selected.

The connection controller 320 checks the subscriber board state of the corresponding slot once more before transmitting the state information of the subscriber board selected by the subscriber information collecting unit 310 to the cell processor 330, and determines that a state change has occurred. Transmits the selection failure of the corresponding subscriber board to the subscriber information collecting unit 310 so that the priority of the subscriber board selection is re-progressed, and if the state change is not detected, the selected slot number is transmitted together with the subscriber board selection completion signal. Transmission to the processor 330 side.

The cell processor 330 selects the subscriber board according to the information applied from the connection controller 320, reads the cell of the corresponding time slot from among the ATM cells stored in the FIFO, and then selects the subscriber board after the predetermined clock. When the multiplexing of the 53-byte cell is completely performed, a signal for cell multiplexing is transmitted to the subscriber information collecting unit 310 so that the multiplexing is performed for the next priority.

In the present invention having the above-described technical configuration, the operation of multiplexing cell information applied from multiple subscriber links is as follows.

The 53-byte ATM cell input through the time slots allocated from the plurality of subscriber links is stored in the FIFO of the corresponding subscriber board 100A-100N, and the fact that the next ATM cell is received is applied to the ATM cell processing unit 300.

In this case, the subscriber information collecting unit 310 of the ATM cell processing unit 300 collects ATM cell information stored in corresponding FIFOs of the plurality of subscriber boards, and then scans the entire cell while increasing the slot numbers for each subscriber board one by one. It is determined whether there exists or not, the priority is given to each subscriber board, and then the information of the selected subscriber board is applied to the connection control unit 320 side.

In the above-mentioned, the priority of each board is equal to the lowest priority of the subscriber board currently being processed by the ATM cell, and the highest priority is given to the subscriber board of the slot for the next processing. To be selected.

The connection controller 320 may change the state of the subscriber board because the state of the subscriber board selected by the subscriber information collecting unit 310 is transferred to the cell processor 330 and the cell processing for multiplexing is performed at the same time. If the subscriber information collecting unit 310 checks the subscriber board state of the corresponding slot once more before transmitting the subscriber board information of the priority selected by the subscriber information collecting unit 310 to the cell processing unit 330, By transmitting the information of selection failure to the subscriber information collecting unit 310, the subscriber board selection of priority is performed again. If the state change is not detected, the cell processor 330 transmits the selected slot number together with the subscriber board selection completion signal. Send to the side.

The cell processor 330 selects a corresponding subscriber board according to the information applied from the connection control unit 320, reads a cell of the corresponding time slot from among ATM cells stored in the FIFO of the corresponding subscriber board, and then sets a predetermined clock. Output the activation signal for performing the multiplexing to the multiplexing board 200 side, and when the multiplexing of the 53-byte cell is completed by the multiplexing board 200 transmits a signal for completion of cell processing to the subscriber information collection unit 310 Allow multiplexing to be performed for the next priority.

As described above, the present invention collects the state information of the subscriber board, and if it is determined that there is a cell that can be transmitted, the priority is given to each subscriber board, thereby multiplexing the ATM cells received from the subscriber link according to the priority. By accepting the board and performing the fast multiplexing process, reliability is provided for the operation of the ATM switching system.

Claims (5)

In the ATM switching system, A plurality of subscriber boards for storing the ATM subscriber cell received from each link in the FIFO, and a multiplexing board for reading and multiplexing the cell information stored in the FIFO of the subscriber board in accordance with the assigned priority, If there is a cell that can collect and transmit information of the plurality of subscriber boards, give priority to each subscriber board, check the information of the corresponding subscriber board once again, determine the corresponding slot number, and activate reading of cell information of the corresponding slot. ATM cell multiplexing apparatus further comprising ATM cell processing means. The method according to claim 1, The ATM cell processing means includes: a subscriber information collecting unit for collecting information of each subscriber board connected to a subscriber link and then assigning priority to each subscriber board in which a transmittable cell exists; A connection control unit which checks the state information of the board selected by the subscriber information collection unit once more to determine whether the selection of the corresponding board is performed normally; A cell that reads a cell of a corresponding time slot from a corresponding subscriber board and transmits the cell to a multiplexing board side according to the information of the connection controller, and when the multiplexing of the corresponding cell is completed, transmits the corresponding information to the subscriber information collecting unit to control multiplexing of the next cell. ATM cell multiplexing device comprising a processing unit. The method according to claim 1 or 2, The priority is given to the last priority for the board processing the current ATM cell, the priority is given to the subscriber board of the immediately next slot ATM cell multiplexing apparatus. The method according to claim 2, And the subscriber information collecting unit increases the slot numbers of the collected subscriber boards one by one and detects the presence or absence of a transmittable cell. The method according to claim 2, And the connection control unit notifies the subscriber information collecting unit that a subscriber board selection is wrong when a state change is detected in the process of re-checking the state information of the selected subscriber board in the subscriber information collecting unit.